Perhaps no Denver Broncos player is more thankful for having a second chance at winning an AFC championship than tight end Clarence Kay is.

The four-year veteran from the University of Georgia was out of action this time last year, while the Broncos were making their run to the Super Bowl, because he was in rehabilitation fighting an unspecified chemical dependence.

He said in an interview this week: "I didn't feel comfortable for a long time after it became public, and sometimes I still don't. But I'm willing to live with it and do whatever is absolutely necessary to stay with my career and pay back the club for sticking with me."

His behavior had become very erratic. "I wasn't risky to be around," he says now, "but you never knew what might set me off." Because he was late so often for team meetings, he says he was fined $14,000 his rookie season, $8,000 the second and $9,000 last season. "I figured, I came with no money, so why care if I leave with none."

Last December, after positive drug test results were given to club officials, Coach Dan Reeves called Kay to his office "and he told me that I was of no use to the team or to myself," Kay said. He added that Reeves issued an ultimatum: if Kay wanted to remain with the club he would rehabilitate under the club's supervision.

"I thought the best way would be to go off somewhere and do it on my own," Kay said, "but that hasn't worked for any number of people . . . Large amounts of money plus free time can be a dangerous combination."

He has said he doesn't mind being drug-tested for as long as the club sees fit.

Reeves said: "Clarence got his hand-eye coordination back after rehabilitation. He runs routes as well as anybody in the game, but the quaterbacks didn't want to throw to him because he couldn't catch a thing.

"I knew he could be a factor {as a receiver} if he could keep his life straight. I told him, 'I don't have to drug test you because if I see you dropping passes again, I'll know things aren't right.' "

Kay caught two touchdown passes Sunday in the Broncos' 34-10 playoff victory over Houston, his first touchdown receptions this season.Wilson Wants to Coach

Note to those in the NFL who claim they're looking for "qualified" blacks to encourage to stay in the coaching ranks: Steve Wilson, Denver's veteran cornerback, feels he has been overlooked long enough.

Wilson, who spent his college days at Howard University, was not drafted and went to the Dallas Cowboys in 1979 as the 24th of 25 free agent wide receivers. He already was depressed that the Redskins, his boyhood idols, didn't invite him to camp as a free agent, then got to Dallas only to find, "I could go three, four days without a pass being thrown to me."

But Roger Staubach noticed Wilson was bright, paid strict attention to detail and ran his routes better than the others. And it was Staubach -- entering his last season -- who took a liking to Wilson and kept him around long enough for the coaches to notice he should make the team.

Although he was later shifted to cornerback, he stuck with the Cowboys from 1979-81 and has been a regular with Denver ever since. He started Sunday against Houston and will probably do so again against Cleveland in the conference title game.

But after being in the league nine years, Wilson, 30, is planning for his second career. He would love to coach, and said: "I'd really like to go back to a black school and help prepare youngsters there."

He also would like a shot at pro coaching. But with contacts in private business all over the country, he has other attractive options should the NFL pass over him again.Black Clothes, Black Days

Houston Coach Jerry Glanville, who wears all black on game days, has attracted the attention of another visible man who is famous for wearing all black, Johnny Cash. Glanville says Cash has been sending him black sunglasses and black jackets all year, and that Cash orders his employees to watch Oilers games, telling them: "That's Johnny Cash football." . . .

Because there are no can't-miss college quarterbacks in this year's class, several clubs could resort to trading for established veterans.

Quarterbacks who could well be traded this off-season: Steve DeBerg of the Buccaneers and Todd Blackledge of the Chiefs seem like locks. Boomer Esiason's salary could make it tough to trade him, but he'd like to leave Cincinnati. Kelly Stouffer, the first-round draft pick who never signed with the Cardinals, could go back into the draft or become a free agent. And now there's the Steve Young-Joe Montana controversy.

The 49ers have to decide whether it's worth more now (in players and, or draft choices) to trade Montana, 31, while he still has top value, or whether to go with two quarterbacks. If Montana winds up being benched, his value will plummet.

Young always could run and has a great arm, but he was having trouble reading defenses and wound up throwing too many passes into heavy coverage. Bill Walsh and his staff have been working with him on his reads, and the problem could well be straightened out by training camp. The Upset Pick

The UP is 1-1 in the playoffs. Minnesota's hot and Cleveland's hot for revenge. The Pick? No way the Redskins lose now. But the Browns will take the Broncos in a classic.